This invention relates to an activation apparatus for valves, specifically electromagnetically-activated multiway valves.
Such activation devices are used specifically as manual operation devices for solenoid valves, so that in case of a failure of the drive medium for the valve element (power failure, defective coil or armature), the valve element can be placed in a position in which fluid pressure may still be introduced to the device being supplied through the electromagnetic valve.
An activation device of the type described above is known from the German Pat. No. DE 21 58 248. This device exhibits, in an open housing recess of a multiway solenoid valve, an indexing pin, which serves as the activation element, and which can be displaced in the direction of its longitudinal axis and can be rotated by a predetermined amount around its longitudinal axis. The indexing pin is provided with a bevelled groove, into which fits a guide pin, which limits the axial movement and the rotational movement of the indexing pin. The mounting for the guide pin is a hole in the housing transverse to the longitudinal axis of the housing recess. By means of gaskets, which are in grooves running in the circumferential direction of the indexing pin, and which are in sealed contact with the wall bordering the housing recess, the escape of pressure fluid through the gap between the wall of the housing recess and the jacket surface of the indexing pin is prevented. The indexing pin exhibits a bevel, by means of which, when the indexing pin is activated, the armature of the valve, designed as the valve element, is raised from the valve seat.
This known device exhibits several elements required for the guidance and mounting of the activation element in the housing recess, which means that the device entails a relatively high fabrication and installation expense.
There must be grooves worked into the activation element to hold the gaskets. The valve housing must be equipped with an additional hole for the guide and safety pin. When the device is being installed, the activation element must first be fitted with the gaskets, and then, avoiding damage to the gaskets, must be introduced and oriented in the housing recess. Finally, the guide and safety pin must be fitted into the hole in the valve housing which serves as the mounting.